So lets hear it. I want to know what you have to say about the validity of subspecies, purpose, origin of concept, what type of biologists follow(ed) it, and how it applies and either conflicts or supports various species concepts.

Are there problems with accepting or not accepting recognition of subspecies? Where[what] are the problems with this concept?

SPECIESSpecies are taxonomic grouping of animals that are similar, but readily distinguishable from another, and which rarely or never interbreed naturally. For example lions and tigers are different species of big cats. Eeven where they occur together (in the Gir forest, India) they are sufficiently different in type and behaviour that they do not interbreed naturally.

Just a little sandwich here for those who constantly use a liger for an example of speciation--anyway, Interbreeding seems to be a good criteria.

SUBSPECIESSubspecies (also known as race) is the taxonomic rank below species. Members of a subspecies differ morphologically from members of other subspecies within the same species, for example the Amur tiger differs in type from the Bengal tiger. However, if they encounter each other, members of the subspecies are sufficiently similar that they readily interbreed.

Subspecies is a classification, and since people differ on how they class things, it will not always be exact or perfect--but I think the criteria of interbreeding or not (in the wild), and not whether they could , but whether they do.

How come (or how) someone can use liger as an example of speciation? :)

One can use it to demonstrate that different species can in certain rare cases have offspring, but I don't see how that proves or disproves anything else. Nobody probably claims tiger and lion are the same species..?

I think if one wants to point out the problems of categorizing species they might want to use certain canines such as dog and wolf as an example: there you have two species who can relatively easily interbreed and have perfectly viable offspring. These dog-wolves have even caused some concern in certain parts of the world, because they are often big and aggressive, but not nearly as afraid of human as wolves are.

Better yet, if you go to the microbial world you'll see that the term species leads to a complete mess :)

But like AFJ pointed out, for general purposes one can pretty safely determine species as groups of animals that do not interbreed naturally. Then again, I don't think a chihuahua and a great dane would interbreed naturally, either ;) (like I already said in another thread).

From a management perspective, ssp is a very valuable classification as it allows us to identify subpopulations that may be at a sensitive stage in their evolution, and thus protect them from man-made disturbance.

What did the parasitic Candiru fish say when it finally found a host? - - "Urethra!!"